Color printers have become increasingly more commonplace with advances in printing technologies. High-quality color printers are readily commercially available in a wide variety of sizes and prices ranging from portable and desktop printers for use at home or at the office, to large commercial-grade printers.
Traditionally, printers were used primarily for printing text documents. Today, however, color printers are available and are routinely used to print complex images, such as digital photographs. Often it is difficult to distinguish color printed images from developed film photographs.
Achieving color uniformity is one of the most challenging aspects in color printing. Evaluating the print quality becomes more challenging when a multi-die print head is used, such as those used for Page Wide Array (PWA) printing. Print quality defects range from die density variation to bands in the image. The bands are introduced by system characteristics such as drop weight variation through the print head, imperfect print head alignment, or chatter in the carriage. Similar non-uniformity banding is seen in piezoelectric print heads.
Evaluating print quality is typically done manually by an experienced technician who grades the print quality visually. Because this approach requires a technician, it can be quite expensive and the results are often inconsistent.